Perfect for keeping coins, keys, or other small items safe and secure when delivering or sending to another person. Made with durable, thick 28 lb paper with no windows to keep contents hidden. Features an extra wide gummed seal to prevent items from falling out and ensure the flap stays closed longer. Number 7 size envelopes measure 3.5 x 6.5 inches, providing plenty of room for multiple keys and legal to send via Usps. paper prevents contents from being shown while remaining light enough for any pen, pencil, or marker to write on for labeling. Weight: 4.4 pounds.